English
Place of Origin: Guangdong, China
Application: Heavy Industry, General Industry, Automotive Industry
Brand Name: KernalCoil Thread Insert
Surface Treatment: Zinc Plated,Plain,Bright(Uncoated),Polished,Customized
Package: Plastic Bag+Carton Box
Material: cold rolled 304/316 stainless steel, hardness RC43-50
Tensile Strength: ≥200,000psi (~1379MPa)
Surface Roughness: Ra≤0.8μm
Temperature Range: -60°C to 800°C (instantaneous peak)
Fitting Tolerance: DIN8140 standard, the accuracy of the internal threads up to 6H
Tapping Depth (L2): usually effective length + 2-3 pitch allowance
Drilling diameter (do): 0.1-0.3mm smaller than the free outer diameter of the screw insert.
Detail
As an elastic coiled fastener, wire thread inserts provide self-adjusting capability to ensure maximum surface contact with individual threads in the host material. This optimized load distribution minimizes stress concentration and fatigue failure while maximizing thread strength, thereby enhancing the reliability and service life of fastened assemblies. The stainless steel construction offers corrosion resistance under normal environmental conditions and mitigates galvanic corrosion in multi-material joints, further extending the system's durability. Standard inserts maintain operational integrity across a temperature range of -320°C to +800°C.
Post-Installation Tolerance
The final thread tolerance of the insert-equipped hole depends on two critical factors:
1. Manufacturing tolerances of the insert profile
2.Thread quality of the installation hole, governed by tapping accuracy (typically achieving ISO 6H class, with precision grades up to 5H/4H or UNJ 2B/3B for unified threads)
Users may select specialized taps, threading methods (manual/machine), and lubrication protocols to achieve required tolerance classes and inspection criteria.
Structural Configuration
Free-State Architecture:
- Coil Body: Precision-formed helical structure from rhombic cross-section wire, generating external threads for host engagement and internal threads for fastener mating.
- Installation Tang: A straight projection bent inward at one end, designed for insert driving. Installation tools engage this tang to radially compress the insert during insertion.
- Lead-In Section: A tapered segment (210° arc from tang) with reduced diameter to facilitate initial thread engagement.
- Tang Notch: Strategically positioned notch (30°–90° from tang) enabling clean tang removal post-installation. This critical feature prevents fastener obstruction while maintaining full thread continuity.
Key Functional Advantages
1. Elastic Deformation Compensation: Accommodates thread pitch deviations through controlled radial expansion.
2. Dual Thread Interface: External threads bond with host material; internal threads provide standardized fastener engagement.
3. Fail-Safe Design: Tang removal mechanism preserves full functional thread profile without secondary machining.
Standards Compliance: ISO 23218, NASM 21266, DIN 8140.
Material Options: 304/316 Stainless Steel (Standard), Inconel 718 (High-Temp), Phosphor Bronze (Non-Magnetic).
There are two methods of representing wire thread inserts, both of which are used to characterize the three key parameters of wire thread inserts: diameter, pitch, and length.
1. Specification Method: For example, M3X0.5X1.5D. This means that after the thread insert is installed, the formed internal thread specification is M3, the pitch is 0.5, and the length is 1.5D (that is, the length is 1.5 times the diameter, and the specific value is 1.5×3 = 4.5mm). The length mentioned here specifically refers to the length after installation.
2. Standard Method: For example, M3X0.5X6.3 turns. It indicates that the internal thread specification is M3, the pitch is 0.5, the number of turns of the thread insert is 6.3 turns, and the corresponding length after installation is also 4.5mm. The number of turns here refers to the actual number of turns of the thread insert before installation.
|
Thread Specification |
Installed Length |
Installed Length |
Number of Turns before Installation |
Outer Diameter before Installation |
Drill Diameter do |
|
M11*0.5 |
1d |
11.0 |
5.7 |
13.0-13.4 |
11.4 |
|
1.5d |
16.5 |
9.1 |
|||
|
2d |
22.0 |
12.5 |
|||
|
M12*1.75 |
1d |
12.0 |
5.3 |
14.3-14.8 |
12.4 |
|
1.5d |
18.0 |
8.4 |
|||
|
2d |
24.0 |
11.6 |
|||
|
2.5d |
30.0 |
14.8 |
|||
|
3d |
36.0 |
18 |
|||
|
M12*1.5 |
1d |
12.0 |
6.2 |
14.3-14.8 |
12.4 |
|
1.5d |
18.0 |
9.8 |
|||
|
2d |
24.0 |
13.5 |
|||
|
2.5d |
30.0 |
17.1 |
|||
|
M12*1.25 |
1d |
12.0 |
7.5 |
14.3-14.8 |
12.3 |
|
1.5d |
18.0 |
11.8 |
|||
|
2d |
24.0 |
16.1 |
|||
|
2.5d |
30.0 |
20.3 |
|||
|
M12*1 |
1d |
12.0 |
9.4 |
14.3-14.8 |
12.3 |
|
1.5d |
18.0 |
14.7 |
|||
|
2d |
24.0 |
19.9 |
|||
|
M14*2 |
1d |
14.0 |
5.4 |
16.7-17.2 |
14.5 |
|
1.5d |
21.0 |
8.7 |
|||
|
2d |
28.0 |
11.9 |
|||
|
2.5d |
35.0 |
15.2 |
|||
|
3d |
42.0 |
18.4 |
|||
|
M14*1.5 |
0.75d |
10.5 |
5.2 |
16.7-17.2 |
14.4 |
|
1d |
14.0 |
7.3 |
|||
|
1.5d |
21.0 |
11.5 |
|||
|
2d |
28.0 |
15.7 |
|||
|
2.5d |
35.0 |
19.9 |
|||
|
M14*1.25 |
1d |
14.0 |
8.8 |
16.7-17.2 |
14.3 |
|
1.5d |
21.0 |
13.8 |
|||
|
M16*2 |
1d |
16.0 |
6.3 |
18.8-19.4 |
16.5 |
|
1.5d |
24.0 |
10.0 |
|||
|
2d |
32.0 |
13.7 |
|||
|
2.5d |
40.0 |
17.5 |
|||
|
3d |
48.0 |
21.2 |
|||
|
M16*1.5 |
0.75d |
12.0 |
6.1 |
18.8-19.4 |
16.4 |
|
1d |
16.0 |
8.5 |
|||
|
1.5d |
24.0 |
13.3 |
|||
|
2d |
32.0 |
18.1 |
|||
|
M18*2.5 |
1d |
18.0 |
5.6 |
21.4-22 |
18.6 |
|
1.5d |
27.0 |
9.0 |
|||
|
2d |
36.0 |
12.3 |
|||
|
2.5d |
45.0 |
15.7 |
|||
|
3d |
54.0 |
19.0 |
|||
|
M18*2 |
0.75d |
13.5 |
5.0 |
21.4-22 |
18.5 |
|
1d |
18.0 |
7.1 |
|||
|
1.5d |
27.0 |
11.2 |
|||
|
2d |
36.0 |
15.2 |
|||
|
M18*1.5 |
0.75d |
13.5 |
7.1 |
21.4-22 |
18.4 |
|
1d |
18.0 |
9.8 |
|||
|
1.5d |
27.0 |
15.0 |
|||
|
2d |
36.0 |
20.3 |